This invention relates to an oil and water separator and more particularly, to an oil and water separator for use in boats for separating oil and water collected in the bilge of a boat prior to discharging the water overboard.
It is important to keep the bilges of a boat dry of both water and oil while at the same time preventing pollution of the water surrounding the boat with the fuel or waste water which has accumulated in the bilge. Lubricating oil leaking from the motor and fuel dripping from leaking lines frequently collect and mix with sea water which has accumulated because of leaking cutlass bearings and hull fittings. There are products on the market now which are designed to absorb the oil from the water prior to the water being pumped overboard but none are efficient enough to prevent rainbows from forming on the surface of the water as a result of small amounts of oil or fuel being discharged with the water that has been separated from the oil and water collected from the bilge. As a result all of the separated oil as well as any water containing small amounts of oil or fuel must be collected and discarded without contaminating the sea or lake.
Federal regulations prohibit a discharge of oil or other pollutants or hazardous substance into the waterways of the United States through the enactment of the Federal Water Pollution Control Act. Such regulations include the prohibitation of pumping, pouring or discharging any kind of oil including fuel oil, gasoline, lubricating oil or oil/water mixtures normally collected in the bilge of marine vessels.
There have been many attempts to separate the oil from the water collected in the bilges of vessels and some prior art devices developed use filtering systems such as disclosed in U.S. Pat. Nos. 3,913,513 and 4,031,839. The inventions disclosed in these U. S. patents include the use of an oil filter for removing the oil pollutants from an oil/water mixture collected in the bilge of a boat wherein the filter has layers of different size expanded resin particles that are hydrophobic and olephilic. However, certain disadvantages are acknowledged to be associated with this type of filtering system which generally relate to the creation of back pressure caused by the filter to resist flow and hinder start-up of the bilge pump. Prior art systems of this type utilizing a filter also include inherent limitations in that a filter element commonly only absorbs approximately 50%-60% of the absorbent potential of the filter structure. Accordingly, the replacement or cleaning of the filter is a constant problem.
In an attempt to overcome the use of filters, oil separators such as shown in U.S. Pat. No. 4,915,823 have been developed. In this particular type of oil separator, the oil and water mixture collected in the bilge of a marine craft is fed into containers wherein the oil and water are allowed to separate mechanically and the water is then drained off the bottom of the receptacle. One problem with such devices is that they are too large for small recreational boats.
Other patents have been located during a search of the records of the United States Patent Office which disclose oil and water separators. Such are U.S. Pat. Nos. 1,494,906, 4,802,978, 4,422,931, 2,428,927, 4,147,629, 2,541,491 and 4,960,513.